JP5594941B2 - Biomass crusher and control method of the apparatus - Google Patents

Description

  The present invention relates to a biomass pulverizing apparatus that pulverizes and pulverizes biomass solids, and a method for controlling the apparatus.

In recent years, CO ₂ emission reduction has been promoted from the viewpoint of global warming. In particular, in combustion facilities such as boiler power generation, fossil fuels such as coal and heavy oil are often used as fuels. However, these fossil fuels cause global warming due to the problem of CO ₂ emissions, and are effective in protecting the global environment. Its use is being regulated from a viewpoint. In addition, from the viewpoint of depletion of fossil fuels, the development and commercialization of alternative energy resources are required.
Therefore, as an alternative to fossil fuels, the use of fuel using biomass has been promoted. Biomass is an organic substance resulting from photosynthesis, and includes biomass such as wood, vegetation, crops, and moss. By biomass-treating this biomass, the biomass can be effectively used as an energy source or an industrial raw material.

  From the viewpoint of highly efficient use of biomass, which is renewable energy, biomass is used as a fuel. One of the methods used as fuel is a method in which biomass solids are pulverized and pulverized and supplied to a pulverized coal-fired boiler for use as fuel. This is known as a single pulverization method in which coal and biomass are separately pulverized, and a mixed pulverization method in which coal and biomass are mixed and then pulverized. In any method, a biomass pulverizer for pulverizing biomass solids is required. However, when an existing mill used in a conventional coal-fired boiler is used, the maximum capacity of the existing mill is limited. It remained at about 3 cal /%. Therefore, unlike existing mills, a biomass pulverization apparatus that can operate biomass efficiently and stably has been desired.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-347241) discloses a pulverizer for pulverizing coal, a coal supply device including a coal supply pipe and a coal bunker for supplying coal to the pulverizer, and biomass in the coal supply pipe. There is disclosed a configuration in which a biomass constant supply unit that quantitatively supplies the biomass is supplied, and the operation state of the biomass crusher is stabilized by adjusting the supply of biomass from the biomass constant supply unit. For example, an apparatus shown in FIG. 5 is used as the biomass crushing apparatus. The biomass solids supplied onto the pulverizing table 202 from the biomass supply pipe 201 are pulverized by the pulverizing roller 203, the pulverized biomass is discharged to the outer periphery of the pulverizing table 202, and conveyed upward by the air ejected from the lower periphery of the table 202. Then, the pulverized biomass is classified into fine powder and coarse powder.
Further, in Patent Document 2 (Japanese Patent Laid-Open No. 2005-113125), a wood type fuel is supplied onto a pulverizing table and crushed by an air flow from below the outer periphery of the table using a vertical pulverizer that pulverizes with a pulverizing roller. A configuration in which an object is conveyed upward and classified into fine powder and coarse powder is disclosed, and here, by setting the relationship between the flow rate of the air flow and the diameter of the grinding table or the area of the table outer periphery The classification performance is improved.

JP 2004-347241 A JP-A-2005-113125

However, in a system in which biomass solids are pulverized and conveyed to a boiler and burned, from the viewpoint of biomass pulverization, drying capacity, and transportability, the biomass state, that is, the moisture content, size, and grade of biomass Accordingly, it is necessary to appropriately adjust the operation state of the biomass crusher, and the operating range is expanded as the amount of air in the biomass crusher as described in Patent Documents 1 and 2 is increased. Therefore, if the amount of air becomes excessive, the combustibility of the fuel deteriorates, and problems such as generation of NO _x and increase in unburned content occur. On the other hand, if the amount of air is too small, excessive pulverization increases the power cost, increases the vibration of the apparatus, and causes an unstable operation state such as power hunting.

Therefore, instead of a system that transports the pulverized biomass from the biomass pulverizer directly to the boiler, the biomass pulverized product discharged and discharged from the biomass pulverizer is separated and recovered from the airflow, temporarily stored in the storage unit, and stored appropriately. Although the system which conveys to a boiler from a part can be considered, in this system, the number of components will increase and it will become a system with low reliability for stable operation.
In addition, compared to pulverized coal, the biomass pulverized product has a large fluctuation in moisture, and may adhere to the transport pipe etc. that transport the pulverized biomass, or the biomass pulverized product is highly flammable. There is a risk of ignition in the pulverizing apparatus or in the conveying pipe, and it has been difficult to perform pulverizing and conveying safely and stably.

  Accordingly, in view of the above-mentioned problems of the prior art, the present invention enables the stable operation by maintaining the classification performance by appropriately setting the amount of air blown into the apparatus, and directly introduces the pulverized biomass into the combustion apparatus. Therefore, an object of the present invention is to provide a biomass pulverization apparatus that enables stable combustion without deteriorating combustion performance even when burning. It is another object of the present invention to provide a biomass pulverization apparatus that can stably operate even with a large amount of moisture fluctuation and is highly safe.

Therefore, in order to solve such problems, the present invention presses and crushes biomass solids supplied on a crushing table that is driven to rotate in a cylindrical housing by a roller that operates in conjunction with the rotation of the table. In the biomass pulverization apparatus that forms a blown airflow with the primary air supplied from the lower part of the housing, conveys the biomass pulverized product upward by the blown airflow and classifies it into coarse powder and fine powder,
A constriction part for expanding and contracting the airflow passage of the blowing airflow is provided above the housing, and the cross-sectional area of the constriction part is set so that the airflow passing through the constriction part is within a predetermined superficial velocity range. An air heater for setting and heating the primary air supplied to the housing, an inlet temperature measuring means for measuring an inlet temperature of the primary air supplied to the housing, and an outlet of the primary air carrying the pulverized biomass Outlet temperature measuring means for measuring temperature, humidity measuring means for measuring the outlet relative humidity of the primary air that has conveyed the biomass pulverized product, and the inlet temperature of the primary air supplied to the housing is 250 ° C. or less, the biomass pulverization A control device for controlling the air heater so that the outlet relative humidity of the primary air transporting the object is 40% or less and the temperature difference between the outlet temperature and the dew point is 20 ° C. or more; Wherein the pulverized biomass device, characterized in that it is directly connected to the combustion equipment of the boiler by the transport tube.

  According to the present invention, when the amount of air blown into the apparatus can be set appropriately, the classification performance is maintained and stable operation is possible, and the biomass pulverized product is directly introduced into the combustion apparatus and burned. However, stable combustion is possible without reducing the combustion performance. That is, by forming the throttle part at the upper part of the biomass pulverizer, it is possible to maintain the speed of the primary air blowing air flow (superficial velocity) without excessively supplying primary air, and stable classification becomes possible. .

Further, the superficial velocity of the throttle part is in a range of 0.5 to 2.0 m / s.
In this way, by setting the superficial velocity of the throttle part within the above range, the classification performance of the biomass pulverizer is maintained, stable operation is possible, and the supply amount of primary air is prevented from becoming excessive. it can. That is, when the superficial velocity is 0.5 m / s or less, the amount of air is too small, causing problems such as over-pulverization, increased device vibration, power hunting, and increased power costs, and the superficial velocity is 2.0 m / s. When it is s or more, a large amount of coarse powder is mixed in the pulverized product, resulting in poor combustibility. Therefore, it is preferable to set within the above range.

Furthermore, it comprises a funnel-shaped funnel extending downward from the upper part of the housing,
A blown airflow passage formed by an outer surface of the funnel and an inner surface of the housing; and a downflow airflow passage formed by the inner surface of the funnel and communicating with the blown airflow passage through an air passage opening at the top of the funnel. ,
The throttle part is formed in the blowing airflow passage by the inclination of the funnel.
In this manner, by forming the throttle portion with a funnel, the throttle portion can be formed with a simple configuration, and can be applied to existing facilities. Moreover, by providing a funnel, it is possible to prevent the blast flow and the downflow in the apparatus from colliding to generate turbulent flow and to maintain a necessary superficial velocity.

Furthermore, the biomass pulverization apparatus is directly connected to a combustion facility of a boiler through a transfer pipe.
Thus, according to the present invention, when the pulverized biomass conveyed to the primary air is directly introduced into the combustion facility, the biomass pulverizer is stabilized within the range of the amount of air required in the combustion facility. It is possible to drive.

Also, the primary air supplied from the lower part of the housing is pulverized by pressing the biomass solids supplied on the crushing table that rotates in the cylindrical housing with a roller that operates in conjunction with the rotation of the table. In the control method of a biomass pulverizing apparatus that forms a blown airflow and conveys the biomass pulverized product upward by the blown airflow and classifies the pulverized biomass into coarse powder and fine powder, an airflow path of the blown airflow is provided above the housing. An expansion / contraction throttle section is provided, and the sectional area of the throttle section is set so that the blown airflow passing through the throttle section is within a predetermined superficial velocity range, and the inlet temperature of the primary air supplied to the housing 250 ° C. or lower, the outlet relative humidity of the primary air transporting the pulverized biomass is 40% or lower, and the temperature difference between the outlet temperature and the dew point is 20 ° C. or higher. And controlled so, the pulverized biomass device, characterized in that it is directly connected to the combustion equipment of the boiler by the transport tube.

In this way, by setting the primary air inlet temperature, outlet relative humidity, outlet temperature, and dew point temperature to appropriate values, stable operation is possible even for biomass with large moisture fluctuations. In addition, safe operation is possible.
Furthermore, the primary air which conveyed the said biomass pulverized material is directly introduce | transduced into the combustion equipment of a boiler via a conveyance pipe, It is characterized by the above-mentioned.

As described above, according to the present invention, it is possible to appropriately set the amount of air blown into the apparatus, maintain the classification performance and enable stable operation, and introduce the pulverized biomass directly into the combustion apparatus. Even in the case of combustion, stable combustion is possible without reducing the combustion performance.
By forming the throttle portion on the upper part of the biomass pulverizer, the primary air blowing air velocity can be maintained without excessively supplying primary air, and stable classification becomes possible. Further, by forming the throttle portion with a funnel, the throttle portion can be formed with a simple configuration, and can be applied to existing facilities. Further, by providing the funnel, it is possible to prevent the blast flow from colliding with the blown airflow and the descending airflow in the apparatus, and to maintain the necessary superficial velocity.
In addition, by setting the primary air inlet temperature, outlet relative humidity, outlet temperature, and dew point temperature to appropriate values, stable operation is possible even for biomass with large moisture fluctuations and is safe. High-performance driving is possible.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
FIG. 1 is a side sectional view showing a schematic configuration of a biomass crushing apparatus according to a first embodiment of the present invention, FIG. 2 is a block diagram showing an example in which the biomass crushing apparatus of the present invention is applied to boiler furnace equipment, and FIG. FIG. 4 is a side sectional view showing a schematic configuration of a biomass crushing apparatus according to a second embodiment of the invention, and FIG. 4 is a diagram showing analysis results regarding each performance of the biomass crushing apparatus according to the second embodiment of the present invention.

(First embodiment)
As shown in FIG. 1, the biomass pulverizing apparatus 1 according to the first embodiment of the present invention has a cylindrical housing 2, and a substantially circular trapezoidal pulverizing table 3 is provided in the lower part of the housing 2. A pulverization roller 5 is provided above the pulverization table 3, and a biomass solids supply pipe 7 and a distributor 6 for classifying the pulverized biomass conveyed by airflow are provided in the upper part of the housing 2. Is provided. In addition, primary air supply means is provided at the lower part of the housing 2, and the primary air supplied therefrom forms an upward flow from below the pulverization table 3. Further, a funnel 8 having a funnel shape is provided above the crushing table 3, and the primary air blowing air passage A and the descending air passage B are separated by the funnel 8.

The pulverization table 3 is formed in a substantially circular trapezoidal shape, and the upper surface of the pulverization table 3 is formed in a concave shape so that the biomass solid matter placed on the table does not spill out. The crushing table 3 is connected to a motor 4 that extends from the lower side of the table, and the crushing table 3 is rotationally driven by the motor 4.
The crushing roller 5 is provided above a position shifted outward from the center of the crushing table 3. While the crushing roller 5 rotates in conjunction with the rotation of the crushing table 3, the crushing roller 5 applies a pressing force to the biomass solid material 100 placed on the table to crush it. At this time, a transmission, an inverter, and a hole change are connected to the motor 4, and a variable hydraulic power source or a spring that changes a pulverization load is connected to the pulverization roller 5. The crushing load of the crushing roller 5 is increased steplessly or stepwise, and the crushing power can be controlled by a control device (not shown) so that the crushing power is within the rated range, preferably substantially constant.

The supply pipe 7 is vertically inserted into the top plate of the housing 2 and is installed so as to drop the biomass solid material 100 onto the crushing table 3.
The distributor 6 secondary classifies slightly fine particles after passing through the air classification (primary classification) with primary air, and is a fixed distributor (cyclone separator) or rotary distributor. A vessel (rotary separator) or the like is used.
The primary air supply means supplies primary air at a predetermined flow rate and a predetermined temperature into the housing 2, and an induction fan or a valve is used to adjust the air flow rate. Moreover, a temperature adjustment means is provided as needed. The air flow rate or temperature is appropriately controlled by a control device (not shown).

A gap 9 is provided between the outer peripheral edge of the pulverizing table 3 and the inner peripheral surface of the housing 2, and the primary air supplied from the primary air supply means blows upward from the pulverizing table 3 through the gap. It has become. Preferably, a drift vane 10 is provided in the gap 9. The drift vane 10 adjusts the blowing direction of the primary air, and more preferably, the angle of the drift vane 10 can be arbitrarily controlled.
The funnel (rectifying plate) 8 is fixed to the upper part of the housing 2 and extends downward. The funnel 8 is formed in a funnel shape and expands and contracts from the top to the bottom. The lower end of the funnel 8 extends to above the crushing table 3. The lower end of the funnel is positioned inside the gap 9 so that the primary air blown up from the gap 9 passes outside the funnel 8, that is, through the blown air flow path A between the funnel 8 and the housing 2.
An air passage 11 is provided in the upper portion of the funnel 8, and a drift vane 12 is disposed in the air passage 11. The drift vane 12 adjusts the blowing direction of the primary air when the primary air that has passed through the blow-up airflow passage A is sent into the funnel 8. Preferably, the angle of the drift vane 10 is arbitrarily controlled. Make it possible. The primary air that has passed through the drift vane 12 is sent to the downflow passage B formed inside the funkel 8.

In the present embodiment, the body diameter of the housing 2, the primary air amount, and the opening area of the blowing airflow passage A are set so that the superficial velocity in the blowing airflow passage A is 0.5 to 2.0 m / s. Set (cross-sectional area).
Further, as another form in which the funnel 8 is not provided, the side wall of the housing 2 may be expanded and contracted upward, and the throttle portion may be formed upward by the housing 2 itself.
In the blow-up airflow passage A, the wind speed of the primary air increases as it goes upward, and the superficial velocity required for classification is sufficiently secured, so that stable classification is performed.

In the biomass pulverizing apparatus having the above-described configuration, the biomass solids 100 are supplied to the central portion of the pulverizing table 3 through the supply pipe 7 and moved on the pulverizing table 3 in the outer peripheral direction by centrifugal force. 3 and the crushing roller 5 are crushed and crushed. Primary air is supplied from the lower part of the housing 2 through primary air supply means, and the primary air passes through the gap 9 and blows into the housing 2 to form an air flow. The pulverized biomass powder is transported to the upper portion of the housing by the blown airflow through the blown airflow passage A outside the funnel 8. Since the blown-up airflow passage A has a constricted portion formed by the funnel 8, a superficial velocity required for classification is ensured even with a small amount of primary air, and classification is performed stably.
Coarse powder (coarse powder) among the powder conveyed to the upper part of the housing 2 falls on the crushing table 3 by gravity and is pulverized again. On the other hand, the fine powder is classified again by the classifier 6 at the top of the housing 2. Fine powder smaller than a predetermined particle size is carried out by a blown-up airflow. Coarse powder larger than a predetermined particle diameter that has not penetrated the classifier 6 falls on the crushing table 3 and is pulverized again.

Here, as an example, FIG. 2 shows a case where the above-described biomass crusher is applied to a system including a boiler furnace.
As shown in FIG. 2, the system according to the present embodiment includes a biomass storage facility 20 that stores primary solid crush (coarse crush) to a predetermined particle size or less and dried biomass solids 100 as necessary, and biomass solids. Biomass pulverizer 1 provided with hopper 21 to which product 100 is supplied, coal pulverizers 27 and 28 provided with hoppers 25 and 26 for receiving coal, biomass powder and coal pulverized obtained by biomass pulverizer 1 A boiler furnace 30 to which the coal powder obtained by the devices 27 and 28 is supplied.
Biomass solids 100 such as wood chips are sized to some extent and stored in the biomass storage facility 20 as biomass chips, and then supplied to the biomass hopper 21. The biomass chips are supplied from the biomass hopper 21 to the pulverization apparatus 1 and pulverized by the pulverization table 3 and the pulverization lawn 5. The pulverized biomass pulverized material and coal pulverized material are supplied to the boiler furnace 30, and the biomass powder and the coal powder are mixed and burned in the boiler furnace 30.

  The furnace body 31 of the boiler furnace 30 is provided with a fuel supply nozzle and a burner that cooperates therewith. The combustion exhaust gas generated by the combustion heats the heat transfer tube 32 arranged in the furnace and is sent to the flue. An air heater (AH) 33 is disposed in the middle of the flue provided at the furnace outlet of the furnace body 31, and the combustion exhaust gas passing through the air heater 33 is released into the atmosphere through an exhaust gas treatment facility such as an ash collector. Is done. High-temperature air 35 generated by heating the outside air 34 by the air heater 33 is supplied to the coal pulverizers 27 and 28 and used for drying the coal. A part 37 of the combustion exhaust gas is supplied to the biomass pulverization apparatus 1 by the attracting fan 36 and used for classification and drying of the biomass.

As described above, according to the first embodiment, the amount of air blown into the apparatus can be appropriately set, the classification performance can be maintained and stable operation can be performed, and the pulverized biomass can be directly introduced into the combustion apparatus. Even in the case of combustion, stable combustion is possible without reducing the combustion performance. That is, by forming the throttle part at the upper part of the biomass pulverizer, it is possible to maintain the speed of the primary air blowing air flow (superficial velocity) without excessively supplying primary air, and stable classification becomes possible. . In particular, by forming the throttle portion with the funnel 8, it is possible to prevent the blast flow from colliding with the blowing airflow and the descending airflow in the apparatus, and to maintain the required superficial velocity. .
Further, when the pulverized biomass conveyed to the primary air is directly introduced into the combustion facility, it is possible to stably operate the biomass pulverizer within the range of air amount required in the combustion facility. .

(Second Embodiment)
FIG. 3 shows a second embodiment of the present invention. In addition, although this embodiment demonstrates the control method of the biomass grinding | pulverization apparatus shown in FIG. 3 as an example, the structure of a biomass grinding | pulverization apparatus is not limited to this, It can apply also to the apparatus which has another structure. Detailed description of the same configuration as that of the first embodiment will be omitted.
The biomass pulverizing apparatus 1 includes a cylindrical housing 2, a pulverizing table 3 provided at the lower part of the housing 2, a pulverizing roller 5 provided above the pulverizing table 3, and biomass provided at the upper part in the housing 2. A solid material supply pipe 7, a dispenser 6 for classifying the biomass pulverized material that has been conveyed by airflow, a funnel 8 having a funnel shape, and primary air supply means provided at the lower part of the housing 2 are provided.

The primary air supply means includes an air heater 18 for heating the primary air, and an induction fan 19 for supplying the heated air into the housing 2.
Furthermore, temperature measuring means 15 for measuring the inlet temperature of the primary air supply means for supplying the primary air to the biomass pulverizing apparatus 1, and temperature measuring means 16 for measuring the outlet temperature, which is a discharge portion of the primary air carrying the pulverized biomass. And a humidity measuring means 17 for measuring the relative humidity of the outlet, and a control device 14 for controlling the air heater 18 based on these measuring means 15, 16, 17 and adjusting the temperature of the primary air. Prepare.

  In the second embodiment, in the biomass pulverization apparatus 1 having the above-described configuration, the temperature of the primary air is adjusted by controlling the air heater 18 so that the temperature measured by the temperature measuring unit 15 is 250 ° C. or less. At the same time, the outlet relative humidity measured by the humidity measuring means 17 is set to 40% or less. Further, the difference between the outlet temperature measured by the temperature measuring means 16 and the dew point temperature is set to 20 ° C. or more.

  The above operating conditions are preferably set from the graph shown in FIG. FIG. 4A is a graph showing the relationship between the total biomass moisture and the primary air temperature, (b) a graph showing the relationship between the biomass total moisture and the outlet air relative humidity, and (c) the relationship between the biomass total moisture and the outlet temperature-dew point. It is a graph to show. With respect to each performance, outlet temperatures of 70 ° C., 75 ° C., 80 ° C., and 85 ° C. are obtained. The air flow rate was constant. As shown to Fig.4 (a), the inlet temperature of primary air becomes proportionally high corresponding to the total water | moisture content of biomass solid substance. The inlet temperature increases as the outlet temperature increases. Conversely, as shown in FIG. 4B, the outlet air relative humidity decreases as the outlet temperature of the primary air increases. Further, as shown in FIG. 4C, the difference between the outlet temperature and the dew point increases as the outlet temperature of the primary air increases. Also, in the graph, the values below the values indicated by the broken lines are the appropriate operating ranges, and the device is operated within this range. The primary air inlet temperature threshold is 250 ° C., which is below the ignition temperature and is a safe operating temperature. The outlet air-related humidity and the threshold value of the difference between the outlet temperature and the dew point are values set based on adhesion. If it is larger than this threshold value, the pulverized biomass tends to adhere to the wall surface of the transport pipe and the like, which hinders operation.

  As described above, according to the second embodiment, by setting the primary air inlet temperature, the outlet relative humidity, the outlet temperature, and the difference between the dew point temperatures to appropriate values, respectively, for biomass with large moisture fluctuations. However, stable operation and safe operation are possible.

If biomass powder grinding apparatus of the present invention is to allow stable operation while maintaining the classification performance by properly setting the amount of air blown into the device, to burn introduced directly pulverized biomass combustion device However, it is possible to perform stable combustion without deteriorating combustion performance, and stable operation is possible even for biomass with large moisture fluctuations and high safety. It is also useful when applied to existing equipment.

It is a sectional side view showing a schematic structure of a biomass crusher concerning a 1st embodiment of the present invention. It is a lineblock diagram showing the example which applied the biomass crusher of the present invention to boiler furnace equipment. It is a sectional side view which shows schematic structure of the biomass grinding | pulverization apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the analysis result regarding each performance of the biomass grinding | pulverization apparatus which concerns on 2nd Embodiment of this invention, (a) The graph which shows the relationship between biomass total moisture and primary air temperature, (b) Total biomass moisture and outlet air relative humidity (C) It is a graph which shows the relationship between biomass total water | moisture content and outlet temperature-dew point. It is a sectional side view which shows schematic structure of the conventional biomass grinding | pulverization apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biomass grinder 2 Housing 3 Grinding table 5 Grinding roller 6 Dispenser 7 Supply pipe 8 Funnel (rectifier plate)
10, 12 Drift vane 14 Controller 15 Inlet temperature measuring means 16 Outlet temperature measuring means 17 Outlet humidity measuring means 18 Air heater 19 Induction fan 21, 25, 26 Hopper 30 Boiler furnace 100 Biomass solid matter

Claims (2)

The biomass solids supplied on the crushing table that is driven to rotate in the cylindrical housing are pressed and crushed by a roller that operates in conjunction with the rotation of the table, and blown up by the primary air supplied from the lower part of the housing. In the biomass pulverization apparatus that forms an air flow, conveys the biomass pulverized product upward by the blowing air flow and classifies it into coarse powder and fine powder,
A constriction part for expanding and contracting the airflow passage of the blowing airflow is provided above the housing, and the cross-sectional area of the constriction part is set so that the airflow passing through the constriction part is within a predetermined superficial velocity range. Set,
An air heater for heating primary air supplied to the housing;
Inlet temperature measuring means for measuring an inlet temperature of primary air supplied to the housing;
Outlet temperature measuring means for measuring the outlet temperature of the primary air that has conveyed the pulverized biomass,
Humidity measuring means for measuring the outlet relative humidity of the primary air that transported the pulverized biomass,
The inlet temperature of the primary air supplied to the housing is 250 ° C. or lower, the outlet relative humidity of the primary air transporting the pulverized biomass is 40% or lower, and the temperature difference between the outlet temperature and the dew point is 20 ° C. or higher. A control device for controlling the air heater,
The biomass pulverizer is directly connected to a boiler combustion facility by a transfer pipe ,
Furthermore, it has a funnel-shaped funnel extending downward from the upper part of the housing,
A blown airflow passage formed by an outer surface of the funnel and an inner surface of the housing; and a downflow airflow passage formed by the inner surface of the funnel and communicating with the blown airflow passage through an air passage opening at the top of the funnel. ,
The throttle portion is formed in the blowing airflow passage by the inclination of the funnel,
The biomass crusher characterized by the superficial velocity of the said narrowing part being in the range of 0.5-2.0 m / s . The biomass solids supplied on the crushing table that is driven to rotate in the cylindrical housing are pressed and crushed by a roller that operates in conjunction with the rotation of the table, and blown up by the primary air supplied from the lower part of the housing. In the control method of the biomass pulverization apparatus that forms an air flow, conveys the biomass pulverized product upward by the blowing air flow, and classifies it into coarse powder and fine powder,
A constriction part for expanding and contracting the airflow passage of the blowing airflow is provided above the housing, and the cross-sectional area of the constriction part is set so that the airflow passing through the constriction part is within a predetermined superficial velocity range. Set,
Control is performed so that the inlet temperature of the primary air supplied to the housing is 250 ° C. or lower, the outlet relative humidity of the primary air transporting the pulverized biomass is 40% or lower, and the temperature difference between the outlet temperature and the dew point is 20 ° C. or higher. And
The biomass pulverization apparatus is directly connected to a boiler combustion facility via a transport pipe, and the primary air is directly introduced into the boiler combustion facility via the transport pipe,
Furthermore, it has a funnel-shaped funnel extending downward from the upper part of the housing,
A blown airflow passage formed by an outer surface of the funnel and an inner surface of the housing; and a downflow airflow passage formed by the inner surface of the funnel and communicating with the blown airflow passage through an air passage opening at the top of the funnel. ,
The throttle portion is formed in the blowing airflow passage by the inclination of the funnel,
The method for controlling a biomass pulverizing apparatus, wherein a superficial velocity of the throttle part is in a range of 0.5 to 2.0 m / s .

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